Hydraulic starter



June 14, 1955 A. c. JENNY HYDRAULIC STARTER 5 Sheets-Sheet 1 Filed May 18% 1954 AOREY June 14, 1955 A. c. JENNY HYDRAULIC STARTER 5 Sheets-Sheet 3 Filed May 18, 1954 5 7/ %fi/ u. A 3 3 8. w: 5 8 no. No. we. .9 mm GE B E \5 mm 8 .8 mm m m 8 Q0 fiawflf mm B on 2. 8 3 a {a g INVENTOR.

ALBERT 0.

BY JENNY M, ATTORNE Unite States Patent 0 Seat HYDRAULIC STARTER Albert C. Jenny, Cleveland, Ohio, assignor of one-third to Charles Greif Raible and one-third to William W. Lytle, both of Chester-land, Ohio Application May 18, 1954, Serial No. 430,624

7 Claims. (Cl. 123-179) This invention relates in general to hydraulic starting devices and is a continuation in part of my co-pending application for Hydraulic Pump or Motor, Serial No. 302,363, filed August 2, 1952.

Hydraulic starting motors usually include a rotatable cylinder barrel having a plurality of pistons reciprocably mounted therein on lines of movement parallel to and spaced around the axis of rotation of the cylinder barrel, the pistons bearing at one end against an angularly positioned thrust, or wobble plate disposed generally coaxial about the axis of rotation. ordinarily in the form of a roller thrust bearing. These motors may be used with hydraulic fluid with a wide range of varying fluid pressures, capable of delivering high torques at high rotational speeds.

In such motors, the mechanical forces involved are usually very high, the mechanical clearances very low and because of the high pressure, the friction losses tend to be excessive. Much of this friction loss is due to the rubbing of the nose of the piston on the bearing surface of the swash plate, which rubbing normally occurs even though a roller thrust bearing for the swash plate is employed.

My invention is particularly adaptable for use in a fluid translating device of the type described in my aforesaid copending application operating in conjunction with a starter pinion gear intended to be selectively engaged with a large gear such as an engine flywheel ring gear, the assembly including means for first engaging the pinion gear and, subsequently, in the same movement, opening my improved hand operated plunger type valve to first admit hydraulic fluid to the motor in small metered degrees for the purpose of very slowly rotating the starter pinion gear to insure its proper mesh with the ring gear, the valve means being so constructed and arranged so as to be self balanced against the hydraulic pressures and so as to admit full volume of hydraulic fluid flow when the starter pinion is in full mesh with the driven engine flywheel ring gear.

it must be appreciated that in devices of this type, extremely high fluid pressures are involved, necessitating the provision of highly eflicient fluid sealing means. I am instantly concerned with sealing means for the plunger ;valve for admitting pressure hydraulic fluid to the engine Within the motor, a plunger valve con- .1.

starting motor. trols the flow of high pressure hydraulic fluid from the fluid inlet into the motor to an outlet chamber leading to the porting plate and the motor to drive the latter. This calls for highly eflicient sealing means, such as 0 rings, surrounding the manually controlled plunger valve between the inlet and outlet chambers. When the plunger valve is in closed position, the seals must prevent any fluid flow and, with the requirement for metered flow between fully closed and fully open positions of the valve, there is a distinct tendency for the high pressure bydraulic fluid to dislodge the sealing rings from the grooves The wobble plate is 2,710,606 Patented June 14, 1955 in the motor housing as the plunger valve is being moved from closed to open position.

One of the primary objects of the present invention is to overcome such a possibility and I have found that one means of accomplishing such an objective is to provide a limited portion of the plunger valve with axially extending and axially chamtered grooves in its outer surface and through the valve barrel to communicate with each other. These grooves are behind the outlet chamber when the valve is closed. These grooves are also behind the 0 ring located between the inlet and outlet ports when the valve is in normally closed position. When the plunger valve is being moved from closed to open position, these grooves permit metered flow, but a sufiicient portion of the outside diameter of the plunger, equal to that of the ungrooved portion or" the valve, ef fectively prevents high fluid pressures from dislodging the rings from their retaining grooves in the motor housing.

Moreover, should the starter jaw, which is manually extended toward the engine flywheel ring gear by the same manual lever that opens and closes the plunger valve, properly mate with the teeth of the ring gear, the gear meshing and plunger valve opening operations are smoothly accomplished by a continuous uninterrupted operation of the manual control lever for those purposes.

There are occasions, however, when the teeth of the starter jaw hit head-on with those of the ring gear, instead of meshing properly. This situation must be rectified by slowly rotating the starter gear until full jaw mesh may be accomplished. it is of prime importance that high speed rotation of the motor and the starter jaw be prevented until full jaw mesh has been obtained, in order to avoid gear ratcheting and resulting destruction of the gear teeth.

It is therefore an important object of my invention to provide a resilient element actuated by the hand control lever for urging the starter jaw toward the engine ring gear and a lost motion connection between the lever and the plunger valve, together with a positive stop on the starter jaw actuating collar, so that when gear abutment, as contrasted to full gear mesh, occurs, no further pres sure is exerted on the starter jaw upon continued application of manual force on the hand control lever, which latter, however, is able to move the valve just far enough to bleed fluid slowly past the O ring seal intermediate the iniet and outlet ports to initiate a slow rotation of the starter jaw just sufliciently to align its teeth with those of the engine ring gear for full jaw mesh.

With the foregoing and other objects in view, the invention resides in the combination of parts and details of construction set forth in the following description and appended claims, certain embodiments being illustrated in the accompanying drawings in which:

Figure 1 is a view in longitudinal section taken through an hydraulic starting motor embodying the present invention, the driven engine gear being shown fragmentarially in approximately its operative relationship to the motor, with the starter pinion being shown retracted to be out of mesh with the engine gear and the metering valve being shown in closed position;

Figure 2 is a view in section taken along line 2--2 of Figure 1, showing the valve and grooves;

Figure 3 is a view taken in section along line 3-3 of Figure 2, showing the valve and grooves;

Figure 4 is a view, generally similar to Figure 1, showing in full lines, the co-related positions of the hand lever, the valve in closed position and the starter jaw retracted out of mesh with the engine ring gear, and labelled Position 1, and in dotted lines, labelled Positions 2 to 5, inclusive, the co-related positions of the valve, lever J and starter jaw from normal at-rest to full jaw mesh and fully opened valve;

Figure is a view, generally similar to Figure 4, representing Position 3, where gear abutment has occurred and the forward end of the valve grooves have passed the 0 ring seal to initiate a slow turn of the starter jaw to permit it to mesh with the engine ring gear; and

Figure 6 is a detail view, partly in side elevation and partly in longitudinal section, of the starter jaw, the hand lever actuated collar and spring and the overrunning clutch. Referring more particularly to the drawings, Figure 1 shows some of the component parts of an hydraulic engine starter including an hydraulic motor, fluid valve metering mechanism and hand control means for meshing the starter pinion and engine flywheel ring gear.

The housing is shown to be generally formed in two parts rigidly bolted together, including a body member 10 and an end plate 11, the body member 10 having a large internal cavity 12, the left end of which is covered over by the end plate 11.

A shaft 14 extends centrally through the cavity 12 and is supported for rotation in the end plate 11 by means of a suitable bearing, such as the needle bearing 15, and at the opposite end in the body member by a suitable hearing such as the ball bearing 16. An 0 ring seal 17 seals the left end of the shaft 14 where it passes through the end plate 11, this sea] preferably being placed between the needle bearing 15 and the cavity 12. In a like manner, a sealing ring 18 is provided on the cavity side of the bearing 16 to effectively prevent the passage of any I,

hydraulic fluid along the shaft 14 to the bearings 15 or 16.

The hydraulic motor comprises generally a cylinder block 20 positioned within the cavity 12 coaxial with the shaft 14 and rotatable therewith, a splined connection 21 being provided between these two members so as to provide a positive driving connection. The cylinder block 20 has a plurality of cylinder bores 23 extending inwardly into the cylinder block from the right hand and, as viewed in Figure 1, having a depth slightly less than the total length of the cylinder block. The cylinder bores 23 all have an axis parallel to the axis of rotation of the shaft 14 and are equi-angularly spaced around the cylinder block 20. A piston 24 is reciprocably supported in each cylinder bore 23, which pistons, in the embodiment shown, are round in shape and generally elongated so as to project beyond the right-hand end of the cylinder block 20 and this end of the piston is formed in the shape of a sphere with the radius of curvature of the end of the piston being equal to one-half the diameter thereof, as specifically disclosed in my aforesaid co-pending application. Further, the pistons have on their external surface a plurality of circumferentially extending grooves 26 which serve to provide a sealing function to prevent or to obstruct the leakage of hydraulic fluid thereby.

The pistons 24 are preferably formed of an aluminum bronze material so as to obtain a soft lubricating action between themselves and the steel of the cylinder block 20 and any other steel parts which they engage during the course of operation of the motor.

The rounded ends of the piston 24 bear against a wobble plate which, in the embodiment shown, is in the form of the movable race 28 of a ball-type thrust bearing, the fixed race 29 of which is based in an angularly disposed recess 30 at the base of the cavity 12. The fixed race 29 and the movable race 28 are separated by a plurality of caged balls which roll in suitable grooves formed in the opposed faces of the two bearing races. Thus, in the embodiment shown, as the cylinder block rotates, the pistons 24 which bear against the face of the race 29 are reciprocated in their cylinder bores 23 and the movable race 28 in a like manner rotates about shaft 14 as an axis.

The base of each cylinder bore 23 has a passage 33 of somewhat smaller diameter than the diameter of the cylinder bore 23 opening to the left-hand side of the cylinder block 20, which passages register alternately as the cylinder block 20 rotates with an inlet port 34 and an outlet port 35 formed in the surface of the end plate facing the cavity 12. The surfaces of the cylinder block 20 surrounding the passages 33 and the surfaces of the end plate 11 immediately adjacent the inlet and outlet ports 34 and 35 are carefully honed and are held in pressure-sealing engagement by the action of the hydraulic pressures in the cylinder bores 23 and a helical compression spring 36 disposed around the shaft 14 and inside of the cylinder block 20, which spring, on its right-hand end, bears against a washer 37 based on a shoulder 38 on the shaft 14 and, on its left-hand end, against a washer 39 based on a split ring .0 expanded into a groove of the cylinder block 20. The inlet port 34 and the outlet port 35 are each generally in the form of a long are corresponding to the path of rotation 33. In the embodiment shown, the outlet port 35 opens into a chamber formed internally of the end plate 11, which chamber in turn, communicates externally of the end plate 11 through passages 46, 47, internally threaded to receive standard, hydraulic fittings 48. Normally, one of the openings is plugged while the other opening has a nose or tube 49 associated therewith to carry away the discharge from the motor to a suitable fluid reservoir, not shown.

In a like manner, the inlet port 34 communicates with an enlarged chamber 50 formed internally of the end plate 11. This chamber 50 communicates through a vertically extending passage 51 in the end plate 11 with a horizontally extending passage 52 in the body 10 at the upper side thereof which, in turn, communicates with a chamber 53 in the body 10 forming the outlet chamber for my novel valve mechanism.

The chamber 50 also communicates externally of the end plate 11 through an opening or passage 54 internal- 1y threaded to receive standard, hydraulic fittings. With the construction shown, it is possible to feed hydraulic fluid to the motor either through the valve mechanism or through the passage 54, as may be desired. if it is desired to feed hydraulic fiuid to the motor only through the valve mechanism, the passage 54 may be suitably plugged or entirely eliminated.

The fluid translating device shown as a preferred embodiment is primarily intended as a starting motor for internal combustion engines having a flywheel ring gear 69, shown in its normal unengaged relationship to the starting motor and adapted to be selectively engaged by a driving starter pinion 611 slidably supported but keyed to an extension of the shaft 14 from the right-hand and by means of a needle bearing 62 supported in a cap 63 forming an extension to the right of the body member 10. The driving pinion 61 is driven through a convert tional overrunning clutch arrangement 64 engaged by means of a collar 65 rotatable with the shaft 14 and axially slidable therealong, by compressing a compression coil spring 96, to move the pinion 61 into engagement with the driven gear 60. The collar 65 is mechanically and ferceably moved along the shaft 1.4 by means of a hell crank lever 66 pivoted on an axis 66 at right angles to the axis of the shaft 14 and slightly thereabove and having a pair of yoke arms 67 extending into the groove of the collar 65. The pinion gear 61 is shown in solid lines in its normally disengaged position relative to the gear 60. It will be noted that in full lines there is a slight spacing between the opposed faces of these gears in Figure l. Movement of the bell crank lever 66 to the left. however, will fully engage the pinion 61 with its driven gear 60. as shown in dotted lines, when proper jam engagement has been effected.

In accordance with the described environment in which my invention has particular adaptability, the valve mechanism is operated in conjunction with and in synchronization with the movements of the pinion 61 into driving engagement with the driven gear 60. Accordingly, the valve mechanism is so positioned and arranged in relation to the bell crank 66 as to be operated thereby. The valve mecha-nism is incorporated in the previously referred to outlet chamber 53 and an inlet chamber 75 to the right of the outlet chamber 53, which inlet chamber communicates with the exterior of the body through a suitable port registering with a suitable hydraulic fitting. The third chamber 52 is disposed on the opposite side of the outlet chamber 53 and the three chambers are all in longitudinal alignment. This last mentioned chamber 52 is, as shown, partially formed in the end plate 11 and has a bleed opening 52 to atmosphere. 9

A plunger valve member 79 is reciprocably supported in the bore 78 and extends from the right-hand side of the body member 10 through the inlet chamber 75, the outlet chamber 53 and into the auxiliary chamber 52. A compression coil spring 80 hearing at its left end against the end plate 11 extends into a hollow end in the valve member 79 and continuously urges this valve member to the right. A spring snap ring 81 fits into a groove formed in the left end of the valve member 79 and coacts with the right-hand end of the chamber 52 to limit the right hand movement of the valve member 79 under the inflence of the spring 80. The cylindrical plunger valve 79 is provided with a plurality of axial grooves 83 extend ing throughout a relatively short length of the plunger valve, but longer than the distance between inlet 75 and outlet 53.

The valve member 79 is shown in its normal, unactuated position by the hand lever 66 when in the position shown in the solid lines of Figure 1. When in this position, the grooves 83 are positioned to the right of the hand side of the outlet chamber 53 and the right-hand side of the auxiliary chamber 52. These 0-rings 87, 88, 89, are all under compression in their respective grooves and provide a sealing action to prevent leakage of hydraulic fluid between the various chambers.

The right-hand end of the valve meber 79 is slotted to form a pair of yoke arms which extend on both sides of the bell crank lever 66 and a pin 91 supported on the bell crank lever 66 extends through openings 92 in the end .of the valve member 79 so that as the bell crank lever 66 is actuated to engage the pinion gear 61 with its driven gear 60, the valve member 79 is also actuated. In the embodiment shown, the opening 92 is loosely fitted with the pin 91 so as to prevent binding due to the curved arc of movement of the pin 92 when the bell crank lever 66 is actuated.

Hydraulic motors of the type in which this invention has particular adaptability normally have unusually high torques, high acceleration and high torques, high acceleration and high rotative speeds which can cause serious damage to the gears 60 and 61 if the gears are not properly meshed in accordance with the application of the hydraulic pressures to the motor. The present fluid valve metering means contemplates a cooperative .relationship between the engagement of the gears and the admission of the fluid pressure to the hydraulic motor wherein each can be under the control of a simple operating lever. Thus, when the bell crank 66 is moved to the left, the valve member 79 moves in the same direction while the pinion 61 moves to the right. The first action occurring is the clearance between the pinion 61 and the gear 60 being taken up. With subsequent movement of the bell crank lever 66, the starter pinion 61 is engaged a predetermined amount with the driven engine flywheel ring gear 60 before the left-hand sides of the grooves 83 have moved sufliciently far to the left to pass the right 6 hand wall of the outlet chamber 53 to establish flow com munication between chambers '75 and 53. In this connection, the wall thickness between the chambers 53 and 75 must be proportioned relative to the desired length of movement of the pinion 61 and the length of the respective distances between the axis of rotation of the bell crank 66 to the respective members which are being moved thereby. It is preferred that the pinion 61 be approximately three-quarters engaged with the driven gear 60 before the left-hand ends of the grooves 83 reach the right-hand wall of the outlet chamber 53. When this does occur, hydraulic fluid under pressure may flow from the inlet chamber 53 and thence to the inlet port 34 to the motor. Further movement of the bell crank lever 66 continues to engage the pinion 61 while, at the same time, further but gradually opening the valve mechanism to allow greater and greater amounts of hydraulic fluid to how to the motor.

In operation, the starter pinion 61 is normally held to the left and is entirely disengaged from the driven engine flywheel gear 60. When it is desired to actuate the starter, the bell crank lever 66 is moved to the left, first simultaneously moving the metering valve 79 to the left and the pinion 61 to the right and into engagement with the driven gear 60. Just prior to the engagement of the gears, a small amount of hydraulic fiuid passes through the grooves 83 in the plunger valve '79 from the inlet chamber 75 into the inlet chamber 53, thus causing the motor to rotate slowly. Further movement of the bell crank lever 66 further engages the gears and eventually the grooves 83 pass into the outlet chamber 53, allowing, at first, a small amount and then, subsequently, larger amounts, as the plunger valve 79 is moved further to the left, of hydraulic fluid to flow into the outlet chamber 53. This fluid passes under pressure from the outlet chamber 53 through the passages 52 and 51 to the chamber 50 internally of the end plate 11. The fluid then passes through the inlet port 34 and enters the cylinder bores 23, forcing the pistons 24 against the plate 28 which, because of the angle of engagement, causes the cylinder block with the pistons therein to rotate about the axis of the shaft 14, thus rotating the shaft 14 and driving the pinion gear 61. After the piston 24 has been moved to the maximum distance to the right in the cylinder bore 23, the passage 33 then moves into engagement with the outlet or exhaust passage and the hydraulic fluid in the cylinder bore 23 is discharged at a high velocity into the chamber and thence externally of the end plate 11.

Whenever it is desired to stop the motor, it is simply necessary to release the-bell crank lever 66 and the spring 80 pushes the valve member 79 to the right and along with it the bell crank which, in turn, will withdraw the pinion 61 from its engagement with the driven gear 60.

K The present valve design, in conjunction with the motor, provides a very simple, mechanically and readily operable arrangement. The grooves 83 are each exposed to the hydraulic fluid pressure in the chamber which provides a balancing arrangement so that when the valve member 79 is moved to the left, it can do so easily and without requiring a force to overcome the hydraulic pressure. Furthermore, the line of movement of the valve member 79 is parallel to the axis of the shaft 14 so that the valve member itself may, by being physically extended, cooperate with the bell crank lever 66 in a positive and simple manner to enable the cooperative and synchronized operation described above.

The salient point with respect to my improvement in my plunger valve 79, over and above the comparable plunger valve disclosed in my aforesaid co-pending application, is the provision of a cylindrical plunger valve of general uniform outside diameter so designed as to effectively cooperate with the sealing 0 rings to close 75 against any leakage from the housing inlet 75 to the outlet 53. More in point, the provision of the especially designed axial grooves 83 in the plunger valve 79 provides for the desired fluid flow metering, as above described, while effectively presenting a sutficient portion of the outside diameter of the plunger valve to be constantly in contact with the 0" ring to prevent its dislodgement from its retaining groove in the motor housmg.

In Figure 6, I have shown one form that the overriding clutch 64 may take. The motor shaft is shown at 14 and carries the starter pinion 61. The housing 64 encloses a plate 99, held therein by a snap ring 100. Two opposed jaws are shown at 102 and 103 are normally held engaged by a strong spring 101, between plate 99 and shoulder 107 of sleeve 105 splined to motor shaft 14, overpowering a lighter spring 104 tending to force the jaws 102 and 103 apart. Surrounding sleeve 105 is a compression coil spring 96 that extends between shoulder 106 of sleeve 105 and shoulder 98 of collar 65 that is slidable longitudinally on sleeve 105 and maintained against removal by a snap ring 95.

In order to more clearly describe the sequence of operation, I have labeled in Figure 4, five positions by number, that the hand lever 66 may assume and the corresponding positions, by number, that the starter pinion and the forward ends of the grooves 83 in the plunger valve may take with respect to ports 75 and 53 and the O ring 88 therebetween. In full lines in Figures 1 and 4, the control handle 66 is shown in normal at-rest position. In Figures 1, 4 and 6, the operating collar 65 is shown in normal at-rest position to urge the left against snap ring 95 by the compression coil spring 96, whose other end bears against shoulder 106 of sleeve 105. This also moves shoulder 98 of collar 65 to a spaced position to the left of a shoulder 97 on the sleeve 105.

In the movement of lever 66 counter-clockwise about pivot 66' from Position 1 to Position 2, the collar is moved from left to right on sleeve 105. This movement is imparted through spring 96 to move the clutch 64 and the starter pinion 61 toward the engine ring gear 60. Should the starter pinion teeth be in full alignment with those of the ring gear 60, the lever 66 may be moved smoothly through Positions 1 to 5, inclusive,

to complete the jaw mesh and full valve volume control.

Should, however, head-on gear tooth abutment occur between the pinion and ring gear, as illustrated by "Posi tion 2, the forward shoulder 97 of collar 65, in compressing spring 96, comes to a full stop against shoulder 106 of sleeve 105, as the pinion teeth 61 are abutting the ring gear teeth in non-rotating relationship. Some slight rotative adjustment is necessary in order to prop erly align the teeth for meshing. Accordingly, the lever 66 may be further moved slightly with the pin 91 moving to the left end of slot 92 to assume "Position 3."

This forces the plunger valve 79 slightly and just enough for the forward ends of the grooves 83 of valve 79 to assume Position 3, or just barely past the O ring seal 88. This permits just enough leakage from port 75 to port 53 to initiate a very slight rotation of the starter motor and pinion so that the latter assumes its Position 3 in mesh with the ring gear. The co-related Positions 4 and 5 show succeeding movements of the lever 66, the depth mesh of the gears and the movement of valve 79 to Position 4, where the grooves just enter port 53 for slow rotation of the motor, but

faster than that which occurs when in Position 2,

and to Position 5 for full valve open volume flow and motor speed.

The fluid translating device described above is simply illustrative of an environment in which my invention is particularly adaptable, but it will become apparent to others upon a reading and understanding of this specification that such modifications and alterations, even though differing radically in appearance from that shown,

come within the scope of the present invention insofar as they are covered by the appended claims.

I claim:

1. In an hydraulic starter for an engine having a gear carried by its crankshaft, a housing, an hydraulic motor and a rotatable shaft driven thereby, a starter pinion mounted on said motor shaft near its outer end, a sleeve arranged inboard of said starter pinion and splined to said motor shaft to be axially slidable on and rotatably driven by said motor shaft, a collar loosely mounted on said sleeve, a clutch drive between said sleeve and said starter pinion, resilient means for normally maintaining said starter pinion out of mesh with said engine gear, a manual lever pivotally connected to said collar to manually move said clutch axially through said resilient means and axially extend said starter pinion into mesh with said engine gear through manually exerted sliding movement of said collar, a fluid inlet port into said housing and a fluid outlet port in said housing leading to said hydraulic motor for driving the motor, a valve mechanism including a plunger type cylindrical valve slidably mounted in a valve bore in said housing, the fluid inlet port and fluid outlet port in said housing being spaced axially and parallel to the plane of sliding movement of the plunger valve in the valve bore in said housing past said fluid inlet port and said fluid outlet port, a portion of its length formed with a plurality of external axially extending grooves, expansive spring means bearing against the housing and the forward end of said plunger valve for normally resiliently urging the plunger valve to a position where its grooved portion is in registry with said inlet port and behind and out of registry with said outlet port, a link and a lost motion connection thereof with said manual lever for connecting the lever to said valve for sliding said valve against the action of said expansive spring means for moving said plunger valve to a position where the grooved portion bridges the intermediate housing wall to establish fluid flow communication between said inlet port and said outlet port to provide a fluid metering means to slowly rotate said pinion gear into gear alignment with said engine gear, after which full operation of the manual lever, prevented during gear abutment, may be had to fully extend the starter pinion into mesh with the engine gear and fully open said plunger valve for full fluid flow to said motor for full speed operation of said motor.

2. In an hydraulic starter for an engine having a gear carried by its crankshaft, a housing, an hydraulic motor and a rotatable shaft driven thereby, a starter pinion mounted on said motor shaft near its outer end, a sleeve arranged inboard of said starter pinion and splined to said motor shaft to be axially slidable on and rotatably driven by said motor shaft, a collar loosely mounted on said sleeve, a clutch drive between said sleeve and said starter pinion, resilient means for normally maintaining said starter pinion out of mesh with said engine gear, a manual lever pivotally connected to said collar to manually move said clutch axially through said resilient means and axially extend said starter pinion into mesh with said engine gear through manually exerted sliding movement of said collar, a fluid inlet port into said housing and a fluid outlet port in said housing leading to said hydraulic motor for driving the motor, a valve mechanism including a plunger type cylindrical valve slidably mounted in a valve bore in said housing, the fluid inlet port and fluid outlet port in said housing being spaced axially and parallel to the plane of sliding movement of the plunger valve in the valve bore in said housing past said fluid inlet port and said fluid outlet port, an annular groove in the internal surface of an intermediate wall portion of the housing surrounding the valve bore between the inlet port and outlet port and a fluid sealing ring seated therein for engagement with the external surface with said valve, said valve having a portion of its length formed with a plurality of external axially extending grooves, expansive spring means bearing against the housing and the forward end of said plunger valve. for normally resiliently urging the plunger valve to a position where its grooved portion is in registry with said inlet port and behind and out, of registry with said sealing ring and the outlet port, a, link and a lost motion'connection thereof with said manual lever for connecting the lever to said valve for sliding said valve against the action of said expansive spring means for moving said plunger valve to a position where the grooved portion bridges the intermediate housing wall to establish fluid flow communication between said inlet port and said outlet port to provide a fluid metering means to slowly rotate said pinion gear into gear alignment with said engine gear, after which full operation of the manual lever, prevented during gear abutment, may be had to fully extend the starter pinion into mesh with the engine gear and fully open said plunger valve for full fluid flow to said motor for full speed operation of said motor.

3. In an hydraulic starter for an engine having a gear carried by its crankshaft, a housing, an hydraulic motor and a rotatable shaft driven thereby, a starter pinion mounted on said motor shaft near its outer end, a sleeve arranged inboard of said starter pinion and splined to said motor shaft to be axially slidable on and rotatably to be engaged by said collar after compression of said spring when gear abutment, and lack of mesh, occurs between said engine gear and said starter pinion upon manual extension of the latter, a fluid inlet port into said housing and a fluid outlet port in said housing leading to said hydraulic motor for driving the motor, a valve mech- L anism including a plunger type cylindrical valve slidably mounted in a valve bore in said housing, the fluid inlet port and fluid outlet port in said housing being spaced axially and parallel to the plane of sliding movement of the plunger valve in the valve bore in said housing past said fluid inlet port and said fluid outlet port, an annular groove in the internal surface of an intermediate wall portion of the housing surrounding the valve bore between the inlet port and the outlet port and a fluid sealing ring seated therein for engagement with the external surface with said valve, said valve having a portion of its length formed with a plurality of external axially extending grooves, expansive spring means bearing against the housing and the forward end of said plunger valve for normally resiliently urging the plunger valve to a position where its grooved portion is in registry with said inlet port and behind and out of registry with said sealing ring and the outlet port, a link and a lost motion connection thereof with said manual lever for connecting the lever to said valve for sliding said valve against the action of said expansive spring means for moving said plunger valve to a position where the grooved portion bridges the intermediate housing wall to establish fluid flow communication between said inlet port and said outlet port to provide a fluid metering means to slowly rotate said pinion gear into gear alignment with said engine gear, after which full operation of the manual lever, prevented during gear abutment, may be had to fully extend the starter pinion into mesh With the engine gear and fully open said plunger valve for full fluid flow to said motor for full speed operation of said motor.

4. In an hydraulic starter for an engine having a gear carried by its crankshaft, a housing, an hydraulic motor ill a sleeve arranged inboard of said starter pinion and splined to said motor shaft to be axially slidable on and rotatably driven by said motor shaft, a collar loosely mounted on said sleeve, an overrunning clutch drive between said sleeve and said starter pinion, a compression coil spring disposed between and bearing against said collar to normally maintain said starter pinion out of mesh with said engine gear, a manual lever pivotally connected to said collar to manually move said clutch axially through said spring and axially extend said starter pinion into mesh with said engine gear through manually exerted sliding movement of said collar, a fluid inlet port into said housing and a fluid outlet port in said housing leading to said hydraulic motor for driving the motor, a valve mechanism, a plunger type cylindrical valve slidably mounted in a valve bore in said housing, the fluid inlet port and fluid outlet port in said housing being spaced axially and parallel tothe plane of sliding movement of the plunger valve in the valve bore in said housing past said fluid inlet port and said fluid outlet port, an annular groove in the internal surface of an intermediate wall portion of the. housing surrounding the valve bore between the inlet port and outlet port and a sealing ring seated therein for engagement with the external surface with said valve, said valve having a portion of its length formed with a plurality of external axially extending grooves, expansive spring means bearing against the housing and the forward end of said plunger valve for normally resiliently urging the plunger valve to a position where its grooved portion is in registry with said inlet port and behind and out of registry with said sealing ring and the outlet port, a link and a lost motion connection thereof with said manual lever for connecting the lever to said valve for sliding said valve against the action of said expansive spring means for moving Said plunger valve to a position where the grooved portion bridges the intermediate housing wall to establish fluid flow communication between said inlet port and said outlet port to provide a fluid metering means to slowly rotate said pinion gear into gear alignment with said engine gear, after which full operation of the manual lever, prevented during gear abutment, may be had to fully extend the starter pinion into mesh with the engine gear and fully open said plunger valve for full fluid flow to said motor for full speed operation of said motor.

5. In an hydraulic starter for an engine having a gear carried by its crankshaft, a housing, an hydraulic motor and a rotatable shaft driven thereby, a starter pinion loosely mounted on said motor shaft near its outer end, a sleeve arranged inboard of said starter pinion and splined to said motor shaft to be axially slidable on and rotatably driven by said motor shaft, a collar loosely mounted on said sleeve, an overrunning clutch drive between said sleeve and said starter pinion, a compression coil spring disposed between and bearing against said collar to normally maintain said starter pinion out of mesh with said engine gear, a manual lever pivotally connected to said collar to manually move said clutch axially through said spring and axially extend said starter pinion into mesh with said engine gear through manually exerted sliding movement of said collar, a fluid inlet port into said housing and a fluid outlet port in said housing leading to said hydraulic motor for driving the motor, a valve mechanism, a plunger type cylindrical valve slidably mounted in a valve bore in said housing, the fluid inlet port and fluid outlet port in said housing being spaced axially and parallel to the plane of sliding movement of the plunger valve in the valve bore in said housing past said fluid inlet port and said fluid outlet port, an annular groove in the internal surface of an intermediate wall portion of the housing surrounding the valve bore between the v inlet port and outlet port and a sealing ring seated therein loosely mounted on said motor shaft near its outer end,

for engagement with the, external surface with said valve, said valve having a portion of its length formed with a plurality of external axially extending grooves that are axially chamfered from each end toward the center, ex pansive spring means bearing against the housing and the forward end of said plunger valve for normally resiliently urging the plunger valve to a position where its grooved portion is in registry with said inlet port and behind and out of registry with said sealing ring and the outlet port, a link and a lost motion connection thereof with said manual lever for connecting the lever to said valve for sliding said valve against the action of said expansive spring means for moving said plunger valve to a position where the grooved portion bridges the intermediate housing wall to establish fluid flow communication between said inlet port and said outlet port while said sealing ring remains in surface contact with the outside diameter of the plunger valve that is commensurate with the valve bore to insure against fluid pressure dislodgment of said sealing ring from its retaining annular housing groove and to provide a fluid metering means to slowly rotate said pinion gear into gear alignment with said engine gear, after which full operation of the manual lever, prevented during'gear abutment, may be had to fully extend the starter pinion into mesh with the engine gear and fully open said plunger valve for full fluid flow to said motor for full speed operation of said motor.

6. In an hydraulic starter for an engine having a gear carried by its crankshaft, a housing, an hydraulic motor and a rotatable shaft driven thereby, a starter pinion loosely mounted on said motor shaft near its outer end, a sleeve arranged inboard of said starter pinion and splined to said motor shaft to be axially slidable on and I- tatably driven by said motor shaft, a collar loosely mounted on said sleeve, an overrunning clutch drive between said sleeve and said starter pinion, a compression coil spring disposed between and bearing against said collar to normally maintain said starter pinion out of mesh with said engine gear, a manual lever pivotally connected to said collar to manually move said clutch axially through said spring and axially extend said starter pinion into mesh with said engine gear through manually exerted sliding movement of said collar, a positive stop shoulder on said sleeve to be engaged by said collar after compression of said spring when gear abutment, and lack of mesh, occurs between said engine gear and said starter pinion upon manual extension of the latter, a fluid inlet port into said housing and a fluid outlet port in said housing leading to said hydraulic motor for driving the motor, a valve mechanism, a plunger type cylindrical valve slidably mounted in a valve bore in said housing, the fluid inlet port and fluid outlet port in said housing being spaced axially and parallel to the plane of sliding movement of the plunger valve in the valve bore in said housing past said fluid inlet port and said fluid outlet port, an annular grove in the internal surface of an intermediate wall portion of the housing surrounding the valve bore between the inlet port and outlet port and a sealing ring seated therein for engagement with the external surface with said valve, said valve having a portion of its length formed with a plurality of external axially extending grooves that are axially chamfered from each end toward the center, expansive spring means hearing against the housing and the formard end of said plunger valve for normally resiliently urging the plunger valve to a position where its grooved portion is in registry with said inlet port and behind said sealing ring and the outlet port, a link and a lost motion connection thereof with said manual lever for connecting the lever to said valve for sliding said valve against the action of said expansive spring means for moving said plunger valve to a position where the grooved portion bridges the intermediate housing wall to establish fluid flow communication between said inlet port and said outlet port to provide a fluid metering means to slowly rotate said pinion gear into gear alignment with said engine gear, after which full operation of the manual lever, prevented during gear abutment, may be had to fully extend the starter pinion into mesh with the engine gear and fully open said plunger valve for full fluid flow to said motor for full speed operation of said motor.

7. In an hydraulic starter for an engine having a gear carried by its crankshaft, a housing, an hydraulic motor and a rotatable shaft driven thereby, a starter pinion loosely mounted on said motor shaft near its outer end, a sleeve arranged inboard of said starter pinion and splined to said motor shaft to be axially slidable on and rotatably driven by said motor shaft, a collar loosely mounted on said sleeve, an overrunning clutch drive between said sleeve and said starter pinion, a compression coil spring disposed about said motor shaft and bearing against said collar to normally maintain said starter pinion out of mesh with said engine gear, a manual lever pivotally connected to said collar to manually move said clutch axially through said spring and axially extend said starter pinion into mesh with said engine gear through manually exerted sliding movement of said collar, a positive stop shoulder on said sleeve adapted to be engaged by said collar after compression of said spring when gear abutment, and lack of mesh, occurs between said engine gear and said starter pinion upon manual extension of the latter, a fluid inlet port into said housing and a fluid outlet port in said housing leading to said hydraulic motor for driving the motor, a valve mechanism including a plunger type cylindrical valve slidably mounted in a valve bore in said housing, the fluid inlet port and fluid outlet port in said housing being spaced axially and parallel to the plane of sliding movement of the plunger valve in the valve bore in said housing past said fluid inlet port and said fluid outlet port, an annular groove in the internal surface of an intermediate wall portion of the housing surrounding the valve bore between the inlet port and outlet port and an 0 ring seated therein for engagement with the external surface with said valve, said valve having a portion of its length formed with a plurality of external axially extending grooves that are chamfered from each end toward the center, expansive spring means bearing against the housing and the forward end of said plunger valve for normally resiliently urging the plunger valve to a position where its grooved portion is in registry with said inlet port and behind and out of registry with said O ring and the outlet port, a link and a lost motion pin and slot connection thereof with said manual lever for connecting the lever to said valve for sliding said valve against the action of said expansive spring means for moving said plunger valve to a position where the grooved portion bridges the intermediate housing wall to establish fluid flow communication between said inlet port and said outlet port, while the O'ring remains in surface contact with the outside diameter of the plunger valve that is commensurate with the valve bore to insure against fluid pressure dislodgment of the O ring from its retaining annular housing groove, and to provide a fluid metering means to slowly rotate said pinion gear into gear alignment with said engine gear, after which full operation of the manual lever, prevented during gear abutment, may be had to fully extend the starter pinion into mesh with the engine gear and fully open said plunger valve for full fluid flow to said motor for full speed operation of said motor.

UNITED STATES PATENTS References Cited in the file of this patent 1,438,325 Nelson Dec. 12, 1922 2,485,504 Morgan Oct. 18, 1949 2,606,736 Ferm Aug. 12, 1952 2,605,108 Stephens July 29, 1952 FOREIGN PATENTS 812,178 Germany of 1951 

